Advances in modern digital hearing aid technology focus almost entirely on improving the intelligibility of speech in noisy environments. The effects of hearing aid processing on musical signals and on the perception of music receive very little attention, despite reports that hardness of hearing is the primary impediment to enjoyment of music in older listeners, and that hearing aid processing is frequently so damaging to musical signals that hearing aid wearers often prefer to remove their hearing aids when listening to music.
Though listeners and musicians who suffer hearing impairment are no less interested in music than normal hearing listeners, there is evidence that the perception of fundamental aspects of (Western) musical signals, such as the relative consonance and dissonance of different musical intervals, is significantly altered by hearing impairment (J. B. Tufts, M. R. Molis, M. R. Leek, Perception of dissonance by people with normal hearing and sensorineural hearing loss, Acoustical Society of America Journal 118 (2005) 955-967). Measures such as the Articulation Index and the Speech Intelligibility Index (American National Standards Institute, New York, N.Y., ANSI S3.5-1997, Methods for the calculation of the speech intelligibility index (1997)) can be used to predict intelligibility from the audibility of speech cues across all frequencies, and a variety of objective tests of speech comprehension are used to measure hearing aid efficacy, but there is no standard metric for measuring a patient's perception of music. Moreover, hearing impaired listeners are less consistent in their judgments about what they hear than are normal hearing listeners (J. L. Punch, Quality judgments of hearing aid-processed speech and music by normal and otopathologic listeners, Journal of the American Audiology Society 3 (1978), no. 4 179-188), and individual differences in performance among listeners having similar audiometric thresholds make it difficult to predict the perceptual effects of hearing aid processing (C. C. Crandell, Individual Differences in Speech Recognition Ability: Implications for Hearing Aid Selection, Ear and Hearing 12 (1991), no. 6 Supplement 100S-108S). These factors, combined with the differences in the acoustical environments in which different styles of music are most often presented, underline the importance of individual preferences in any study of the effects of hearing aid processing on the perception of music. There have been studies on the effect of reduced bandwidth on the perceived quality of music (J. R. Franks, Judgments of Hearing Aid Processed Music, Ear and Hearing 3 (1982), no. 1 18-23), but no systematic evaluation of the effects of dynamic range compression, the most ubiquitous form of gain compensation in digital hearing aids.
There is a need in the art for an improved system for programming hearing assistance devices which incorporates the listener's preferences and provides the listener a convenient interface to subjectively tailor sound processing of a hearing assistance device. There is also a need in the art for a system for hearing assistance devices that allows for better appraisal of the processing of music. Such a system will provide benefit for the fitting of other sound processing technology in hearing assistant devices for which the fitting to hearing loss diagnostics is unknown but for which fitting can be made based on assessment of subjective preference.